Backhoes, excavators and similar type vehicles have an extendible or articulated arm with a bucket attached at an end thereof remote from the operator. Generally, a rotation link is associated with the arm. The bucket is pivotally attached to the arm by a clevis which serves as a pivot point for the bucket. The rotation link is also pivotally attached to the bucket so that movement of the rotation link causes the bucket to rotate about the arm pivot point. With such an arrangement, the bucket can be rotated relative to the arm in a generally vertical, forwardly extending plane defined by the arm and the rotation link, but lateral tilting of the bucket is not possible, at least without tilting of the vehicle. The arm and rotation link are usually not laterally tiltable relative to the vehicle to which they are attached.
There are occasions, however, when it would be very desirable to work with the bucket tilted to the left or right, such as when necessary to adjust for slope requirements or to do side angle grading. It is, of course, undesirable and often not possible to laterally tilt the entire vehicle to achieve tilting of the bucket.
This problem has been overcome with the advent of laterally tiltable buckets. Such buckets generally include a hinge adaptor which is attached to the arm and the rotation link, much in the same way buckets were directly attached in the past. The adaptor serves as a hinge and pivotally supports a bucket for lateral rotation of the bucket about a hinge axis which is generally aligned with the forward rotation plane through which the bucket is conventionally rotated. This allows the bucket to be laterally tilted from side to side. Control of the amount of lateral tilting is accomplished using a double-acting cylinder which extends laterally between the high adapter and the bucket to selectively cause the bucket to rotate about the hinge axis. Extension of the double-acting cylinder causes the bucket to rotate to one side, and retraction of the cylinder causes it to rotate to the other side.
To achieve the desirable range of tilting, such an arrangement has required a relatively long, double-acting cylinder. As such, only relatively wide buckets could accommodate the amount of extension and retraction of the double-acting cylinder required to laterally tilt the bucket to the extent desired. The more tilting required, the greater the space required to handle the double-acting cylinder to be used, because greater extension is needed. Of course, space limitations not only limit the length of the double-acting cylinder which can be used but also the torque output achievable with the cylinder. The use of a bucket that is wide enough to accommodate the elongated double-acting cylinders does not always solve these problems, because certain type jobs can best be done only with relatively narrow buckets. Typically, it is desired to have tiltable buckets tilt 45 degrees to the left and to the right relative to the vertical.
It will therefore be appreciated that there has been a significant need for a laterally tiltable bucket assembly which uses a relatively narrow width bucket. Furthermore, it is desirable that the bucket assembly be able to transmit a large torque to the bucket and firmly hold the bucket at the desired tilt angle. The present invention fulfills these needs and further provides other related advantages.